Obviously, Harry himself. His memories of his parents, his time at Hogwarts, and his battles against Voldemort could be explored in more detail. Also, Dumbledore. His past is full of mysteries, and his memories could hold secrets about the history of the wizarding world and his own actions against dark magic.
The Marauders (James, Sirius, Remus, and Peter). Their memories of their time at Hogwarts, their pranks, and their friendship could be a great focus. We could see their memories of becoming Animagi, for example. Also, Ginny Weasley. Her memories of being possessed by Voldemort's diary and her growth as a witch would be interesting to explore.
Luna Lovegood. Her unique perspective and experiences could lead to some interesting memories. Maybe her memories of her mother, or her encounters with magical creatures that others don't believe in. And Severus Snape. His memories of his love for Lily, his time as a Death Eater and his double - agent role are rich with potential for a fanfic.
The children of the original main characters are often focused on. For example, James, Albus, and Lily Potter. Their experiences at Hogwarts and how they live up to their parents' legacies are common themes.
Harry Potter is usually still a main focus. After all, he's the hero of the original series. Hermione Granger and Ron Weasley are also often central characters. Their friendship with Harry and their own relationship are likely to be explored further.
Harry Potter himself is often a central focus. Since he's the main character in the original series, it makes sense that in time loop fanfics, his experiences in the loop are explored. Hermione Granger is also common. Her intelligence and problem - solving skills are often put to the test in the time loop scenarios. And of course, Ron Weasley, as Harry's best friend, is frequently involved as well.
Well, in 'Harry Potter Magical Puberty Fanfic', Harry Potter is usually a central figure. After all, he is the Boy Who Lived. His experiences with magical puberty can be a great source of exploration. Hermione Granger is also commonly focused on. Her intelligence combined with the changes of puberty can lead to some interesting character development. Ron Weasley too, as his insecurities might be amplified or changed during this time. And sometimes, characters like Draco Malfoy can also be a focus, especially when it comes to how his relationships with the main characters shift during their pubertal magical growth.
Winky the house - elf. She has a lot of potential. In a fanfic, we could explore her life after being freed from the Crouch family. Maybe she has some unique knowledge about the Dark Arts or the Triwizard Tournament that she's been hiding. Her loyalty and her struggle with her new - found freedom could be really interesting to write about.
Hermione is also a popular character in these fanfics. Many alternate endings might show her in different relationships, not just with Ron. Maybe she could have a more independent life, traveling the world to study different forms of magic and using her intelligence to solve global wizarding problems.
Typically, Harry is the main character as his journey through different levels of magical maturity is a major draw. But other characters like Luna Lovegood can also be focused on. Her unique view of the magical world and how it changes as she matures can be really interesting to read about. Also, Draco Malfoy might be a character of interest, seeing how his upbringing in a dark - influenced family affects his path to magical maturity.
Definitely Harry Potter himself. He was the hero of the war, so his post - war life would be of great interest. Also, his friends like Ron and Hermione. They were always by his side during the war, and they would likely continue to be important in his post - war life.
I think Neville Longbottom is a bit underrated in this book. A fanfic could focus on his growth during this time. He could have some secret knowledge about the plants in the Hogwarts grounds that helped in some way during the events. Also, Seamus Finnigan could be interesting. What if he had some family connection to the events in the Prisoner of Azkaban? Maybe his family knew something about Sirius Black or the Dementors. And Crookshanks is another character. A fanfic could be about his adventures around Hogwarts, and how he was actually more intelligent than people thought and was trying to solve the mystery of Sirius Black himself.
Well, Dumbledore could be a very engaging character in 'Back again' fanfics. He has so much knowledge and power, and if he were to go back, he could potentially prevent a lot of the tragedies that occurred. Neville Longbottom is also a great choice. He could use his new - found courage and knowledge from the future to be a real hero earlier on. And Ginny Weasley, she could change her own story and her relationship with Harry in interesting ways if she goes back in time.